///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2015 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Restrictions:
///		By making use of the Software for military purposes, you choose to make
///		a Bunny unhappy.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref gtc_round
/// @file glm/gtc/round.inl
/// @date 2014-11-03 / 2014-11-03
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////

namespace glm {
    namespace detail {
        template<typename T, precision P, template<typename, precision> class vecType, bool compute = false>
        struct compute_ceilShift {
            GLM_FUNC_QUALIFIER static vecType<T, P>
            call(vecType<T, P> const & v, T)
            {
                return v;
            }
        };

        template<typename T, precision P, template<typename, precision> class vecType>
        struct compute_ceilShift<T, P, vecType, true> {
            GLM_FUNC_QUALIFIER static vecType<T, P>
            call(vecType<T, P> const & v, T Shift)
            {
                return v | (v >> Shift);
            }
        };

        template<typename T, precision P, template<typename, precision> class vecType, bool isSigned = true>
        struct compute_ceilPowerOfTwo {
            GLM_FUNC_QUALIFIER static vecType<T, P>
            call(vecType<T, P> const & x)
            {
                GLM_STATIC_ASSERT(!std::numeric_limits<T>::is_iec559,
                                  "'ceilPowerOfTwo' only accept integer scalar or vector inputs");

                vecType<T, P> const Sign(sign(x));

                vecType < T, P > v(abs(x));

                v = v - static_cast<T>(1);
                v = v | (v >> static_cast<T>(1));
                v = v | (v >> static_cast<T>(2));
                v = v | (v >> static_cast<T>(4));
                v = compute_ceilShift<T, P, vecType, sizeof(T) >= 2>::call(v, 8);
                v = compute_ceilShift<T, P, vecType, sizeof(T) >= 4>::call(v, 16);
                v = compute_ceilShift<T, P, vecType, sizeof(T) >= 8>::call(v, 32);
                return (v + static_cast<T>(1)) * Sign;
            }
        };

        template<typename T, precision P, template<typename, precision> class vecType>
        struct compute_ceilPowerOfTwo<T, P, vecType, false> {
            GLM_FUNC_QUALIFIER static vecType<T, P>
            call(vecType<T, P> const & x)
            {
                GLM_STATIC_ASSERT(!std::numeric_limits<T>::is_iec559,
                                  "'ceilPowerOfTwo' only accept integer scalar or vector inputs");

                vecType < T, P > v(x);

                v = v - static_cast<T>(1);
                v = v | (v >> static_cast<T>(1));
                v = v | (v >> static_cast<T>(2));
                v = v | (v >> static_cast<T>(4));
                v = compute_ceilShift<T, P, vecType, sizeof(T) >= 2>::call(v, 8);
                v = compute_ceilShift<T, P, vecType, sizeof(T) >= 4>::call(v, 16);
                v = compute_ceilShift<T, P, vecType, sizeof(T) >= 8>::call(v, 32);
                return v + static_cast<T>(1);
            }
        };

        template<bool is_float, bool is_signed>
        struct compute_ceilMultiple {
        };

        template<>
        struct compute_ceilMultiple<true, true> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source > genType(0)) {
                    genType Tmp = Source - genType(1);
                    return Tmp + (Multiple - std::fmod(Tmp, Multiple));
                } else
                    return Source + std::fmod(-Source, Multiple);
            }
        };

        template<>
        struct compute_ceilMultiple<false, false> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                genType Tmp = Source - genType(1);
                return Tmp + (Multiple - (Tmp % Multiple));
            }
        };

        template<>
        struct compute_ceilMultiple<false, true> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source > genType(0)) {
                    genType Tmp = Source - genType(1);
                    return Tmp + (Multiple - (Tmp % Multiple));
                } else
                    return Source + (-Source % Multiple);
            }
        };

        template<bool is_float, bool is_signed>
        struct compute_floorMultiple {
        };

        template<>
        struct compute_floorMultiple<true, true> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source >= genType(0))
                    return Source - std::fmod(Source, Multiple);
                else {
                    genType Tmp = Source + genType(1);
                    return Tmp - std::fmod(Tmp, Multiple) - Multiple;
                }
            }
        };

        template<>
        struct compute_floorMultiple<false, false> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source >= genType(0))
                    return Source - Source % Multiple;
                else {
                    genType Tmp = Source + genType(1);
                    return Tmp - Tmp % Multiple - Multiple;
                }
            }
        };

        template<>
        struct compute_floorMultiple<false, true> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source >= genType(0))
                    return Source - Source % Multiple;
                else {
                    genType Tmp = Source + genType(1);
                    return Tmp - Tmp % Multiple - Multiple;
                }
            }
        };

        template<bool is_float, bool is_signed>
        struct compute_roundMultiple {
        };

        template<>
        struct compute_roundMultiple<true, true> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source >= genType(0))
                    return Source - std::fmod(Source, Multiple);
                else {
                    genType Tmp = Source + genType(1);
                    return Tmp - std::fmod(Tmp, Multiple) - Multiple;
                }
            }
        };

        template<>
        struct compute_roundMultiple<false, false> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source >= genType(0))
                    return Source - Source % Multiple;
                else {
                    genType Tmp = Source + genType(1);
                    return Tmp - Tmp % Multiple - Multiple;
                }
            }
        };

        template<>
        struct compute_roundMultiple<false, true> {
            template<typename genType>
            GLM_FUNC_QUALIFIER static genType
            call(genType
            Source, genType Multiple)
            {
                if (Source >= genType(0))
                    return Source - Source % Multiple;
                else {
                    genType Tmp = Source + genType(1);
                    return Tmp - Tmp % Multiple - Multiple;
                }
            }
        };
    }//namespace detail

    ////////////////
    // isPowerOfTwo

    template<typename genType>
    GLM_FUNC_QUALIFIER bool isPowerOfTwo(genType Value) {
        genType const Result = glm::abs(Value);
        return !(Result & (Result - 1));
    }

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<bool, P>
    isPowerOfTwo(vecType<T, P>
    const & Value) {
    vecType<T, P> const Result(abs(Value));
    return
    equal(Result
    & (Result - 1),
    vecType<T, P>(0)
    );
}

//////////////////
// ceilPowerOfTwo

template<typename genType>
GLM_FUNC_QUALIFIER genType
ceilPowerOfTwo(genType
value)
{
return

detail::compute_ceilPowerOfTwo<genType, defaultp, tvec1, std::numeric_limits<genType>::is_signed>::call
(tvec1<genType, defaultp>(value))

.
x;
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
ceilPowerOfTwo(vecType<T, P>
const & v)
{
return
detail::compute_ceilPowerOfTwo<T, P, vecType, std::numeric_limits<T>::is_signed>::call(v);
}

///////////////////
// floorPowerOfTwo

template<typename genType>
GLM_FUNC_QUALIFIER genType
floorPowerOfTwo(genType
value)
{
return
isPowerOfTwo(value)
? value :
highestBitValue(value);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
floorPowerOfTwo(vecType<T, P>
const & v)
{
return
detail::functor1<T, T, P, vecType>::call(floorPowerOfTwo, v
);
}

///////////////////
// roundPowerOfTwo

template<typename genIUType>
GLM_FUNC_QUALIFIER genIUType
roundPowerOfTwo(genIUType
value)
{
if(
isPowerOfTwo(value)
)
return
value;

genIUType const prev = highestBitValue(value);
genIUType const next = prev << 1;
return (next - value) < (value - prev) ? next :
prev;
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
roundPowerOfTwo(vecType<T, P>
const & v)
{
return
detail::functor1<T, T, P, vecType>::call(roundPowerOfTwo, v
);
}

////////////////
// isMultiple

template<typename genType>
GLM_FUNC_QUALIFIER bool isMultiple(genType Value, genType Multiple) {
    return isMultiple(tvec1 < genType > (Value), tvec1 < genType > (Multiple)).x;
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<bool, P>
isMultiple(vecType<T, P>
const & Value,
T Multiple
)
{
return (Value % Multiple) ==
vecType<T, P>(0);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<bool, P>
isMultiple(vecType<T, P>
const & Value,
vecType<T, P> const &Multiple
)
{
return (Value % Multiple) ==
vecType<T, P>(0);
}

//////////////////////
// ceilMultiple

template<typename genType>
GLM_FUNC_QUALIFIER genType
ceilMultiple(genType
Source,
genType Multiple
)
{
return
detail::compute_ceilMultiple<std::numeric_limits<genType>::is_iec559, std::numeric_limits<genType>::is_signed>::call(Source, Multiple
);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
ceilMultiple(vecType<T, P>
const & Source,
vecType<T, P> const &Multiple
)
{
return
detail::functor2<T, P, vecType>::call(ceilMultiple, Source, Multiple
);
}

//////////////////////
// floorMultiple

template<typename genType>
GLM_FUNC_QUALIFIER genType
floorMultiple(genType
Source,
genType Multiple
)
{
return
detail::compute_floorMultiple<std::numeric_limits<genType>::is_iec559, std::numeric_limits<genType>::is_signed>::call(Source, Multiple
);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
floorMultiple(vecType<T, P>
const & Source,
vecType<T, P> const &Multiple
)
{
return
detail::functor2<T, P, vecType>::call(floorMultiple, Source, Multiple
);
}

//////////////////////
// roundMultiple

template<typename genType>
GLM_FUNC_QUALIFIER genType
roundMultiple(genType
Source,
genType Multiple
)
{
return
detail::compute_roundMultiple<std::numeric_limits<genType>::is_iec559, std::numeric_limits<genType>::is_signed>::call(Source, Multiple
);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
roundMultiple(vecType<T, P>
const & Source,
vecType<T, P> const &Multiple
)
{
return
detail::functor2<T, P, vecType>::call(roundMultiple, Source, Multiple
);
}
}//namespace glm
